The purpose of this Guide is to address the association of window film with two highly publicized glass failure problems: thermal stress fracture and insulating glass seal failure, and to provide a procedure for examining the advisability of installing window film in a specific situation. For the purposes of the discussion presented herein, window film is divided into two different types: clear safety film and heat-absorbing solar control film.

Heat-absorbing solar control film can be any combination of tinted, coated, or spectrally selective film. The procedure presented for determining the advisability of installing window film in a specific situation involves the investigation of several critical points regarding the glazing conditions and characteristics of the window installation. Based on the results of this investigation, a conservative decision can be made as to whether or not it is advisable to install window film in a particular application. If the use of window film is judged to be a poor risk based on criteria presented herein, it is recommended that the window film manufacturer be contacted regarding the proposed installation or film choice. More rigorous analyses performed by manufacturers representatives or informed consultants can result in more liberal recommendations for the use of window film. The window film manufacturer should be considered the final authority on whether or not to install window film and the proper type of window film to be installed.